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%I #17 May 05 2016 04:26:43
%S 29,113,419,503,659,887,1277,1361,1433,2141,2213,2687,3851,4007,4397,
%T 4787,5333,5417,5573,7127,7757,7829,8609,8693,8849,9161,9311,9623,
%U 10247,10487,11261,11423,12197,12743,13217,13523,14537,14621,14771,15083,15161
%N Primes p such that (p^2 + p + 1)/13 is prime.
%C Primes in A002642.
%H Seiichi Manyama, <a href="/A272629/b272629.txt">Table of n, a(n) for n = 1..1000</a>
%e a(1) = 29 because (29^2+29+1)/13 = 67 is a prime.
%t Select[Prime[Range[5000]], PrimeQ[(#^2 + # + 1) / 13] &]
%o (PARI) lista(nn) = {forprime(p=2, nn, if ((denominator(q=(p^2 + p + 1)/13)== 1) && isprime(q), print1(p, ", ")););} \\ _Michel Marcus_, May 05 2016
%Y Cf. A002642.
%K nonn
%O 1,1
%A _Vincenzo Librandi_, May 04 2016